Malaria is commonly associated with poverty and also a cause of poverty. It is a major hindrance to economic development of tropical and subtropical regions, including parts of America, Asia and Africa. Recent estimates revealed that more than 3.2 billion people are at risk of malaria, with 200 million infections per year, while approximately 0.6 million deaths per year were recorded according tothe World Health Organization ( WHO).This has led to investigations of the potential of natural product-based chemotherapeutic agents to ameliorate the effects of malaria and also in anticipation that new drugs may certainly emerge from the tropical plant sources. The ethanolic extracts of Alstonia boonei leaves and stem were used for this study; qualitative phytochemical analysis was carried out alongside acute toxicity and suppressive effect. The mice were administered 200mg/kg, 400mg/kg and 800mg/kg body weight of leaf and stem bark extracts separately, positive control mice were given standard drug chloroquine (5mg/kg) and the negative control were given distilled water. Phytochemical analysis showed that the stem and leaves of Alstonia boonei had some compounds in common and also had some differences. After 24 hours of acute toxicity, the test mice neither died, showed any sign of toxicity nor any strange behavior. This result showed that the Alstonia boonei was safe and the lethal dose was >5000mg/kg. The suppressive treatment showed that the leaf and stem bark extracts of Alstonia boonei were dose independent. The stem extract of Alstonia boonei was more effective at the dose of 200mg/kg body weight and the leaf extracts were more effective at the dose of 400mg/kg body weight. The standard drug (chloroquine) used for both test extracts gave 100% suppression. Comparatively, the standard drug at certain dose level was more effective compared to both extracts.

Variation of Thermophysical Properties with Porosity in Unconsolidated Materials Using A Transient Method Approach

This study investigated the variation of thermal conductivity and thermal diffusivity of unconsolidated quartz with porosity. The transient method, which involves the application of constant heat flux to a surface of a rectangular container, made of an insulator at the outer edges and covered on the side surfaces by thin sheets of aluminium, containing the samples was employed in determining the thermal conductivity. Results indicate a decrease in thermal conductivity and diffusivity as porosity increased.

Transient Flow and Mass Transfer of a Third Grade Fluid Past a Vertical Porous Plate in the Presence of Chemical Reaction

The effects of chemical reaction and suction, on the transient flow of an incompressible third grade fluid past a vertical porous plate, are studied. The governing time-based coupled partial differential equations are discretized using an efficient and unconditionally stable Crank-Nicolson finite difference scheme and the resulting algebraic nonlinear equations are solved by the modified Newton's method. The velocity and species concentration profiles are computed, graphically presented and discussed in detail for various values of embedded pertinent flow parameters. It is concluded that the fluid velocity decreases with increasing suction and viscoelastic second grade parameters while it increases with an increase in the Schmidt number, solutal Grashof number and third grade parameter. However, as the Schmidt number, suction and rate of chemical reaction parameters increase, they decrease the species concentration of the flow field.

Vessels, parenchyma and ray cells of eighteen woody plant species belonging to 14 families (8 Orders) in Nigeria were studied using light microscopy. Configuration of ray cells, vessel diameter, pitting pattern of the vessels and parenchyma position in relation to the vessel pores are useful taxonomically and they can be linked to the various uses of the woods. Multiseriate ray cells were common in the Order Gentianales e.g. Alstonia congensis, (Apocynaceae) and Mitragyna ciliata (Rubiaceae). Family Fabaceae e.g. Brachystegia eurycoma and Piptadeniastrum africanum have paratracheal parenchyma, absence of cell inclusions and solitary or clustered vessels in common. Order Lamiales e.g. Family Lamiaceae: Tectona grandis and Boraginaceae: Cordia millenii have homogenous ray cells and banded paratracheal parenchyma with no inclusions. These characters may contribute to understanding the incertae sedis situation surrounding appropriate placement of Boraginaceae in an Order. Cleistopholis patens (Annonaceae) and Pycnanthus angolensis (Myristicaeae) in the Order Magnoliales have scalariform vessels and multiseriate ray cells, usually with some inclusions. Order Malpighiales e.g. Anthostema aubryanum and Mallotus oppositifolus (Euphorbiaceae) and Lophira alata (Ochnaceae) have apo- or paratracheal parenchyma and also possess inclusions in the ray cells and vessels while absence of cell inclusions distinguishes the family Malvaceae (Ceiba petandra and Triplochiton scleroxylon) from Sterculiaceae (Mansonia altissima and Pterygota macrocarpa). Multiseriate and homogenous ray cells characterized the Order Myrtales e.g. Combretaceae (Terminalia superba). Moraceae (Ficus platyphylla) and Ulmaceae (Celtis zenkeri) in the order Rosales have multiseriate ray cells and apo- or paratracheal parenchyma. These wieldy plant identification criteria will be useful in taxonomy and archaeology.

In this study, the equilibrium and the dynamics of the adsorption of cationic (Safranin-O also known as Basic Red 2 (BR2)) and anionic (Orange G (OG)) dyes onto unmodified Kaolinite clay (UKC) and Chitosan modified kaolinite (CMK) were investigated. The pH played an obvious role in the adsorption capacities of both UKC and CMK for both dyes, where BR2 dye adsorbed onto both adsorbents was maximum at alkaline pH. When the equilibrium data were fitted into Langmuir and theFreundlich isotherm models, both isotherms provided good correlations for the adsorption of the dyes. Equilibrium data fitted well to Langmuir and Freundlich isotherms with respect to the charge on the dyes. The maximum adsorption capacity for the BR2 dye by the UKC and CMK clay were 33 mg/g and 37 mg/g respectively.

Heavy metals have been mostly evaluated in terms of farm site types and locations, but have not been related to the depth of ill-health they pose to the populace. However, there is inadequate information on human health risk index associated with the consumption of heavy metal contaminated vegetables. This study was conducted to evaluate the heavy metals; Pb, Cd, Cr, Cu, Zn and health risk associated with the consumption of Amaranthus hybridus vegetables in different farm sites. Four selected vegetable farms: Mokola, Ojoo, Olorunda Aba and Agbon-Ile in Ibadan, Nigeria were used during rainy and dry seasons for eight weeks, respectively while Soil from Teaching and Research Farm, University of Ibadan, Ibadan, Nigeria was used to plant the control in the Screen house (control site) of the Department of crop Protection and Environmental Biology. Data collected were analysed using descriptive statistics. The results indicated that heavy metal concentrations in those farm sites were higher in water, soil and vegetables (root and shoot) when compared with the control during dry and rainy seasons. Irrigation water obtained from all the four farms except control had a highly significant amount of Pb concentrations ranging between 96.83 – 116.90mg/L and lower Cd 0.06- 0.12mg/L, while the heavy metals were not detected in the control during both seasons. Results from the soil analysis revealed significantly highest concentration of Pb (128.36mg/kg), while Cd had lower concentration value of 0.40mg/kg and the control had the lowest value (0.12mg/kg) of Pb. Heavy metals detected in vegetables grown in Ojoo farm were significantly higher than those found in other farms including the control. The concentrations of heavy metals in vegetable root samples from all the farms followed the same trend Zn>Cu>Cr>Pb>Cd in both seasons, respectively. The human Health Risk Index (HRI) values were <1 in the vegetable samples (root and shoot) from Agbon-ile, Mokola and Olorunda-Aba in both seasons. However, the HRI was >1 for Pb and Zn (ranged from 1.15-8.32) at Ojoo farm site during the dry and rainy seasons. This study showed that the proximity of Ojoo vegetable farm to heavy traffic road appeared to be the major contributory factor to its high heavy metal accumulation which resulted to high Health Risk Index.

The Nigerian Government indicated interest to transform neem tree into wealth. To achieve this objective, literature search was carried out on the researches conducted on the neem tree and the extent of use in higher institutions and research centres. For fair evaluation, Nigeria was divided into four zones North central / Federal Capital Territory; North East/ North West; South West; South South and South/East. Data were collected by visiting selected Universities and Research Institutes, Libraries, Departments and contact with researchers located in each zone. It was observed that most researches were on use of the plant in Agriculture. The use of extracts of either the neem leaves or seed oil or bark of the root for soil amelioration and adjuvant in livestock, broilers, rabbits and rat feeds; Insecticidal, repellant and antifeedant effects of Neem extract were reported. Chemical studies conducted revealed the presence of carotene, vitamin C, alkaloids, flavonoid, anthraquinone, tannin, saponin, carbohydrates and sapogenins and some elements. On the medicinal use of neem, researchers reported antimalarial, antibacterial, antifungal and antioxidant activities. The toxicological studies conducted reported higher liver and kidney function biochemical parameters especially using fruits extracts. All the zones reported the agricultural uses of neem but there were more data from North East/ North West zone while more literature on the medicinal use and chemical composition were collected from South South and South/East but other zones examined all aspects of the uses of neem and the chemical composition of neem tree. The review revealed duplication of research efforts by researcher across the country and need for products formulation from neem.

Field Establishment and Early Nut Yield of Cashew (Anacardium occidentale, Linn.) as Affected by Nut-Size and Planting Method in Rainforest Agroecological zone of Nigeria

Cashew is a commodity tree crop traded worldwide for its nuts. Field establishment failures had since been limiting expansion of the crop's plantations. Three field establishment methods (ball-of-earth transplants, bare-rooted transplants and direct-seeding) of cashew raised from three nut-sizes (jumbo: >16g, medium: 4g-8g and madras nut-sizes: <2g) were tried. These two factors were factorially combined to give nine treatment combinations. Directly-seeded nuts were sown same day with those of ball-of-earth and bare-rooted transplants that were sown in nursery. The experiment was laid out in randomized complete block design with three replicates. Data were taken, for a period of three years, on morphological growth, % survival, % flowering and early nut yield. Growth of the seedlings was in favour of larger nut-sizes. At 36 Months After Sowing (MAS), ball-of-earth transplant of jumbo was between 11.0% and 18.6% taller than transplant of medium and 20.6% and 21.6% taller than transplant of madras nut-sizes. Directly-seeded seedlings of each of the nut-sizes were almost of the same height with those of ball-of-earth while their bare-rooted transplants were of reduced height throughout. Within 3 Months After Transplanting (MAT), a range of 88.9-100% of ball-of-earth transplants survived transplanting operations, while a range of 50-100% of bare-rooted transplants survived and a range of 66.6–77.8% of directly-seeded seedlings survived. At 12MAT, percentage survival reduced to 38.9–88.9% (bare-rooted transplants), 61.1-66.6% (directly-seeded plants) and 72.2-100% (ball-of-earth transplants). Emergence of reproductive organs was observed at 18MAT, ball-of-earth transplants ofmadras recorded highest percentage flowering (22.2%) followed by that of medium (16.7%). At 24MAT, all the plants flowered with ball-of-earth transplants of medium-nut size having highest percentage(58.3%) and at 30MAT, directly-seeded plants of jumbo had highest percentage flowering (86.7%) followed by ball-of-earth transplants of medium (80.6%). Ball-of-earth and bare-rooted transplants of jumbo recorded highest nut yield at 24 and 36MAT and the differences were all significant (P<0.05). Cashew nuts of jumbo and medium nut-sizes are proven materials for early field establishment and ball-of-earth transplanting results in improved growth and precocity on the field.

Electrical Resistivity and VLF-EM Methods for the Study of Spread of Some Heavy Metal Contaminants in an Old Lead-Battery Dumpsite

Abstract

Electrical Resistivity and VLF-EM Methods for the Study ofSpread of Some Heavy Metal Contaminants in an OldLead-Battery Dumpsite

*J.A. ADEGOKE AND E.O. OLUFOSOKANDepartment of Physics, University of IbadanDepartment of Physics, Lead City University, Ibadan.*Corresponding AuthorE-mail: adegokeja@yahoo.com

This study highlights the application of vertical electrical sounding (VES) and Very Low Frequency Electromagnetic (VLF-EM) methods as mapping tools for detection of subsurface conductive layers and depth of heavy metal contamination at Lalupon Lead dumpsite located at the outskirt of Ibadan, Oyo State, Southwestern Nigeria. In all, fourteen VLF-EM traverse lines were established with a portable ABEM WADI meter and fourteen VES were conducted using a resistivity meter around the perimeter of the dump site with maximum distance of 150m at an interval of 15m from the dump site outwardly. Water taken from hand dug well around the dumpsite were analyzed to determine the concentration of heavy metals (Pb, Zn, Cr, Cu, and Mn). Computer iteration of the sounding data was obtained using WINRESIST 1.0 version on data from partial curve matching on bi-logarithmic graph. Results from Southern region showed increase in resistivity in the first layer and relatively low resistivity in the second layer ranging from 6.1 ?m – 53.4 ?m and thickness 2.6 m – 7.8 m which correlate with the conductive subsurface structural zones as shown by VLF-EM results. The control experiment indicated an aquiferous area while the water analysis suggestsdominance of Pb (2.92 mg/l) and Mn (0.55mg/l) when compared with WHO and SON standard in well Y; therefore, results of the investigation indicate that the contaminant was spreading in the Southern region of the dump site.

Effect of Calcium Carbonate and Ammonium Phosphate on the Flammability and Mechanical Properties of General-Purpose Polystyrene (GPPS)

The plastics industry has been challenged by restrictions on or complete ban placed on the use of halogenated flame retardants because of their adverse health, safety and environment effects and requirement of higher loading for inefficient aluminium and magnesium hydroxides. Recently, there is renewed interest in using safe, readily available, cheap and efficient inorganic flame retardants, most especially ammonium salts as flame retardants for the commodity polyhydrocarbon thermoplastics. In order to produce a flame retardant GPPS, 220ìm-thick pure (additive-free) polystyrene film was prepared by compression moulding technique in this work. Varying amounts of calcium trioxocarbonate (IV) (CaCO ) and ammonium tetraoxophosphate (V) [(NH ) PO ] were added, singly and in combination, to 3 4 3 4 the pure polystyrene pellets to prepare 9 films of the same thickness by the same technique. Flammability tests (vertical burn, limiting oxygen index and horizontal burn) and mechanical properties (tensile strength and elongation-at-break) were investigated according to UL 94 and ASTM standards to evaluate the efficacy of the two fillers on all the 10 prepared sample films. The experimental results showed that flammability properties of the untreated polystyrene sample have been enhanced by both fillers, alone or in combination. In addition to enhancement of ?ame retardance, dripping resistance of the treated samples was also imparted in direct proportion to the loading of the two fillers. The synergistic effect of the two fillers resulted to attainment of V-0 rating and an increase in both the limiting oxygen index and horizoncal burn time of the filled samples. The synergism in flame retardance efficacy of the two fillers are attributed to the release of the two inert gases of ammonia (NH ) by ammonium tetraoxophosphate (V) [(NH ) PO ] and carbon (IV) oxide (CO ) by calcium 3 4 3 4 2 trioxocarbonate (IV) (CaCO ) when the treated general-purpose polystyrene sample films burn. The 3 mechanical properties (tensile strength and elongation-at-break) of the CaCO and (NH ) PO -filled 3 4 3 4 GPPS samples were improved when the two fillers were used singly or in combination in comparison to the pure (control, untreated) GSPS film. The slight improvement in the mechanical properties of the treated samples indicated the compatibility of the two fillers and the pure GPPS resin.